Retarder for flue-tubes.



UNITED STATES PATENT oEEIoE.

. I' l f r i HEINRIQESEGELKEN, OF BRMERHAVENfGERMANY, ASSIGNOR OF ONE-THIRD T0 .FRANZ KWNIGK, or HoBoKEN',

NEW JERSEY,' AND ONE-THIRD T0 HERMANN BEYERSDORFF, OF BREMERHAVEN, GERMANY.

-RETAEDER Fon' anon-TUBES.

Specification of Letters Patent.

Patented Mar. is, reis.

Application med october 25, 191e. serial No. 727,644.

To all whom it vmayiconoem Be it lmown that l, HEINRICH SEGELKEN,

a'subject ot the German Emperor, and a(N resident of Bremerhaven, Germany, haye invented a new and useful improvement 1n vRetarders for Flue-'lubes in Steam-Boilers,

of which the following is a specification.

My invention -relates to 'retarders for the dues or smoke tubes of steam boilers i. e., to devices to be introduced into said flue tubes for the purpose of retarding or slowing the progress of the 'combustion gases through said tubes in such a manner as to cause said gases to yield up their heat units more completely to the flue tube walls and td the water in contact therewith than would be the case were the retarder vnot used.

The preferred form of retarder constitutes a sort of screw within the iiue tube and'comprises a strip ot sheet metal twisted about its axis 'and inserted -in the iiue tubes. lt thus converts the straight flue channel into two semi-circularly sectioned channels spirally twisted upon one anotherl and each having a length lsubstantially greater than that of the due tube itself. Retarders of this description do not, however, fully meet the requirements of maximum eiciency and to that lend are constructed as hereinafter more particularly described.

The object of my invention is to provide a retarder which shall not only slow the combustion gases in their progress through the tube so as to secure the greater absorption of heat units due to an extended timecontact of the hot gases withy the walls of the tube, but also to provide a means of mixing the gases together during their progress through the tube so as to secure a better after burning of the gases, or, in other words, a better and more complete combustion of the gases as they pass through the tube. More particularly, my invention has for its object to bring 'about such mining by means of the construction of the.

My .invention will be better understood by referring to the accompanying drawings in which.- i

Figure l shows a horizontal central longitudina-l section through a. single flue tube of a steam boiler, the retarder being shown as a fiat strip to illustrate the course of the gases through the tube; 2 represents a plan view of myretarder, the strip beingy shown in its twisted form; Fig. 3 represents an axial horizontal section through a iue tube as shown in Fig. l, on a 'greatly enlarged scale; Fig. 4 represents a transverse section taken along the line lof Fig. 3; and Fig. 5 represents, in elevation, part ot the end ost the boiler taken from the smoke box end and showing due tubes provided with my retarder.

Referring to the drawings, l is the hout tube sheet and 2 the rear tube sheet of a due tube boiler; 3 the fire box'end and 4 the smoke box end; 5 a due tube running from front to rear tube sheet and connecting the lire box and smoke box;V and 6 a preerred form of my improved retarder within the :tine tube.

AThe retarder '6 is of metal, preferably sheet iron, and comprises a straight strip Y of length (after twisting) substantially that of the iiue tube and width substantially equal to the internal diameter of said tube and so dimensioned that it can bereadily inserted and withdrawn. Spaced centrally along the strip are ears 7,`72, 73 etc. alternately pressed toward opposite' sides of the strip so as to make a suitable angle a with said strip. These ears are punched out from the strip so that each ear leaves an opening 7a, 7b, 7 etc. in said strip. AThe exact dimensions and configuration of these ears relative to the strip and to the iiue tube may be varied to suit conditions, but l End that ears of the general relative dimensions and of the shape shown are satisfactory.

The ears 7, 72, 73 etc. may be punched from the strip in any usual way after which the strip is given a suitable uniform twist about its central longitudinal axis. lt is cut off to have a length substantially equal to the flue tube and inserted within said tube.

To secure the bestresults the edge of the loo retarder end at the smoke box end should be vertical as seen in Figs. 2 vand 5; the gases trom the two spiral channels oit the 'flue tube will thus emerge from the 'tube and ascend in the smoke box with equal ease. Preferably the edge of the retarder pass through the tube, part on one side of said strip and part on the other. rlhe gases on the one side (Fig. 3) travel parallel to the axis of the tube save tor the twist due to the twist of strip 7 until they reachthe rst ear 7 when they are deflected toward the wall of the tube, as indicated bythe arrow 9; the gases are crowded over the end and around the edges of the gear 7. but retarded, while on the other side ot' said ear there will be established, according to well known principles, a region of relative rareiaction or lowered pressure. flue tube on the other side of the strip 7 when they reach the first opening' "i"l will, Aowing to the low pressure region or suction adjacent to the` ear 7', in part dow through said opening as indicated by arrow lOto mingle with the gases whichfhave passed over the first-ear 7', on the first named side of the strip; and in part continue 0n tothe second ear 72 where they will, in turn, be deflected toward the wall of the due tube and be joined by and mixed with gases passing through the second opening 7b. from the irst named side of the strip And as' the gases continue to flow through the flue tube, this alternate to and tro movement 'of the gasesacross the strip through the openings and consequent repeated' mixing of the divided streams will also continuevuntil they emerge into the smoke box. ylFhis constant mixing ot the gases tends to edect their more perfect combustion as they pass through the tube. The defiecting ears, also, bring the gases more perfectly `in contact with the walls of the fine tubes so that ,the heat units are more completely absorbed thereby. The retardation of the gases due to the ears as well as that due to the .twist also tends to a more complete yielding up of the heatunits in the gases to the flue tubeV walls. To secure the best results, the angle a between ears and strip should be suitably adjusted by bending the ears away from or toward the strip. Should too much steam be generated, the' angle should be increased, and should too little steam be' enerated, the angle should be decreased. imilarly, the amount of twist per unit length oi retarder may be altered, if desired.

Preferably, all the due tubes should be provided with retarder-s if the maximum eztlonger used.

The gases entering the behind said ears.

` Loaders "ciency is to be obtained. iin practice, in

'irst adjusting the retarders to a given `boiler, however, ll find it well to omit ret-arders from one or two lower rows of flue? tubes until a good adjustment of the retard ers has been edected, whereupon all the tubes are filled with such adjusted retarders. l/Vhen ruiming under forced draft, the revtarders may be removed from the lower,

rows, but restored when. forced draft is no 'lhese retarders are particularly adapted for marine boilers but can be profitably employed in any boiler of the flue tube type.

in practical use, l have secured by the use of these retarders a reduction, in the case of an Atlantic liner olfy about 60 tons of coal per 2d hours, for'the same or rather an increased production of steam as comparedwith the coal consumed using a retarder without the ears and opeiiings.- 'llhe heat atthe smoke box was simultaneously reduced by about 750 C.

l claim: y

l. ln a boilera iiue tube provided with a central wall to form a pair ot passages :tor the lire gases, retarding means projecting from said wall for the gases in each passage, v and means tor causing someof the gases in each passage to pass through the walls there of behind lthe retarding means so as to mix with gases of the lother passage.

2. ln a boiler, the combination of a tlue tube, and a strip inclosed by said tube, said y strip being provided with a plurality of 10o spaced projecting ears and also with openings adjacent to and partially overlapped by said ears for the purpose described.

3. lln a boiler, the combination of a luetube, and a strip inclosed by said tube, said 105 strip' being provided with a plurality of spaced ears alternately 'projecting toward opposite sides and being also provided with a plurality of openings located immediately 4. lin a boiler, the combination 'ot a flue tube and a spiral strip inclosed by said ue tube, said trip being provided with a plu-` rality ot spaced openings and ears adjacent thereto projecting toward opposite sides and adjustably united with said strip. j f

5. llna boiler, the combination of a ue tube and a spiral strip inclosed by said flue tube, said strip being provided with a plurality of spaced openings and ears adja- 12o cent thereto, projecting toward opposite sides in the"`same general direction as dened by the passage of the gases through the tube. A

6. ln a boiler, the combination of a iiue tube and a spiral strip inclosed by said flue tube, said strip being provided with a plu rality of spaced openings and' ears adjacente thereto, projecting toward opposite sides in the same general direction'as. defned by the 130 passage of the gases through -the tube, the end edges of the stripstanding verticali)T in the tube.

7. As an article off manufacture a retarder comprismg a metallic strip providedl with ears disposed along said strp projecting alternately from opposite si es thereof the baseof said ears rising said ears terminatingwithn the confines of an imaginary circle of whichnthe width of the strip is a diameter and a series of perforations, one for each ear, said perforations from an imperforate part ofsaid strip and the ee end of lying on corresponding sides ofsaid ears relatively to the length of the strip, the ar-4 i Y HEINRioH SEGELKEN. Witnesses:.

Jos. F. BUCK,

HEINRrGH SGHMEDEN.

.rangement being such that the ears are 10- Y 

